Generally, a vehicle is provided with a starter motor for revving an engine thereof and with an alternator for generating electricity using the rotational force of the engine. In a starter motor, an ignition switch is connected to a battery as a power source by an operation of a driver when a vehicle is started, and a driving force, which is generated by supplying power to the starter motor through the ignition switch, rotates an engine to start the engine.
On the other hand, an alternator is connected to a driving unit of the engine, a rotor is rotated by the driving force of the engine in a state in which a magnetic field is formed, so that an alternating current power is generated, and the battery is charged with the generated alternating current power using a rectifier or the like.
Both the starter motor and the alternator are configured to have a structure of a stator and a rotor, and structures thereof are very similar. The starter motor and the alternator may operate as generators or motors according to whether force is applied or electric power is applied.
Recently, research has been actively conducted on a structure of a belt driven starter generator (BSG) (hereinafter referred to as BSG) which serves as both a starter motor and an alternator in one structure.
Meanwhile, a rotor-winding synchronous type motor is a motor in which coils are wound around a protrusion protruding from an outer circumferential surface of a rotor core, and is mainly used as a generator. Recently, however, the development of non-rare earth motors has received attention, and has been proposed as a form of traction motor.
Coils wound around the rotor are connected through terminals of a bus bar disposed on the rotor. Further, blades may be provided on the rotor to cool heat that is generated in the coils wound around the rotor. However, since a configuration of the rotor is complex, there are problems in that manufacturing processes of the rotor are complex and manufacturing costs are increased due to an increase in the number of parts.